作者机构:[1]School of Mathematical Science and Computing Technology, Central South University, Changsha 410083,China, [2]School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing100083, China
相关基金:This work was supported by the National Natural Science Foundation of China (Nos. 50874123 and 51174236) and National Basic Research Program of China (No. 2011CB606306).